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Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
Large-Scale Exploration Targeting for Uranium Mineral Systems within the
Eromanga Basin.Simon van der Wielen
With contributions from: Alison Kirkby, Allison Britt, Anthony Schofield, Roger Skirrow, Evgeniy Bastrakov, Andrew Cross, Malcolm Nicoll, Terry Mernagh, Andrew
Barnicoat.
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
Talk Outline
• Sandstone hosted uranium system model• Locality map• Methodology on how the Eromanga 3D map
was constructed• Eromanga Basin geology• Prospectivity Analysis:
– Euroka Arch region– Lake Eyre region
• Conclusions
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
Conceptual Sandstone U System Models
Single fluid model• Oxidised fluid carrying
Uranium.
• In-situ reductant.
Two fluids model• Oxidised fluid carrying
Uranium.• Reduced (hydrocarbons
or H2 S) fluid acting as a reductant.
Figures courtesy of Subhash Jaireth
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
Locality Map Study Area
NW Corner: -150,000 mE;
-1,250,000 mN.
SE Corner: 1,700,000 mE;
-3,800,000 mN.
Eromanga Basin:
1,224,506 km2
Surat Basin:
257,460 km2
Carpentaria Basin:
696,090 km2
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
AREA REDUCTION: How do we reduce the area from size of western Europe (~2,000,000 km2) to the size of Monaco (~2 km2)???
1000 * 1000 * 10001000 kmkm
100 * 100 * 100100 kmkm
10 * 10 * 1010 kmkm
1 * 1 km1 * 1 km
Literature Review and Literature Review and National DatasetsNational Datasets
Review of Australian Phanerozoic Basins.
Data Compilation, Data Compilation, Regional DatasetsRegional Datasets Major Basin Architecture, Large
Scale REDOX Gradients and Fluid Flow Pathways.
Data acquisition, Data Data acquisition, Data processing and processing and interpretationinterpretation
Increase CostIncrease Cost
DESCOVERYDESCOVERY
DRILLINGDRILLING
Chemical Gradients, Lithological Traps,
Structures, etc.
etc
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
The Approach…
1. Integrate existing datasets into a 3D environment (this case gOcad)
2. Use existing datasets to build a 3D map of the Eromanga Basin
3. Identify what datasets can be used to map the major mineral system ingredients
4. Produce a 3D minerals system assessment for the Eromanga Basin
5. Ground truthing: Conduct detailed geochemical and petrographic studies over areas highlighted to determine whether a uranium mineral system has been active
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
Data Model
MineralGeological LogsWire-line Logs
Analytical
MineralGeological LogsWire-line Logs
Analytical
PetroleumGeological LogsWire-line Logs
Analytical
PetroleumGeological LogsWire-line Logs
Analytical
StateSurveys
Stratigraphic PicksData Compilations
StateSurveys
Stratigraphic PicksData Compilations
BRSHydrogeochemicalStratigraphic Picks
Wire-line Logs
BRSHydrogeochemicalStratigraphic Picks
Wire-line Logs
GADEM
Surface GeologyGeophysics
GADEM
Surface GeologyGeophysics
Eromanga “Common
Earth”Model
Eromanga Eromanga ““CommonCommon
EarthEarth””ModelModelProblems:
1. No consistent formats.
2. Data is of variable quality.
3. Data is difficult to find (not readily searchable).
Figure courtesy of Malcolm Nicoll
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
Stratigraphic Framework
01_Ksrw (Winton)
00_DEM (Topography)
02_Ksrm (Mackunda)03_Klro (Toolebuc)04_Ksr (Rolling Downs)05_Ksco (Cadna-owie)06_Jsyh (Hooray)
07_Jsbh (Hutton)
08_Rsmo (Moolayember)09_Rsl (Clematis)
10_Basement
Radke et al., 2000
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
01_Ksrw (Winton)
02_Ksrm (Mackunda)
03_Klro (Toolebuc)
04_Ksr (Rolling Downs)
05_Ksco (Cadna-owie)
06_Jsyh (Hooray)
07_Jsbh (Hutton)
08_Rsmo (Moolayember)
09_Rsl (Clematis)
Production of a 3D Production of a 3D Geological Block Model Geological Block Model
(gOcad voxet)(gOcad voxet)
Vertical Exaggeration = 50 times
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
Targets
• Target One– Euroka Arch
• Target Two– Lake Eyre Region
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
Euroka Arch• DEM surface• Geology• Natural Gamma
– Logs (black)– Gridded Data
• Radiometrics– Uranium on DEM
• Hydrochemistry– Points– Gridded Uranium
50 km
N
Mt Isa Inlier
Georgetown Inlier
Uranium mg/L0 2Natural Gamma API0 250
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
Lake Eyre• DEM Surface• Geology• Hydrochemistry
– Points– Gridded Eh– Gridded Ba– Gridded pH– Gridded U
Lake Eyre
Eh (mV)-600 600Barium (mg/L)0 0.25pH (mV)4 10Uranium (mg/L)0 15
50 km
N
Large-Scale Exploration Targeting for Uranium Mineral Systems within the Eromanga Basin
Conclusions• Applying Mineral System concepts reduces
exploration risk by rapidly decreasing the search area
• First time disparate datasets for the Eromanga Basin have been integrated and visualised together
• The Eromanga 3D Map has potential applications to other geoscience research: – Geothermal prospectivity– Petroleum prospectivity– Groundwater studies– Carbon Capture and Storage (CCS) studies